KR20030011666A - Method and mold for molding of plastic articles - Google Patents

Abstract

PURPOSE: A forming method of a product and its mold are provided to improve the durability by removing a flaking event of a heating layer and an insulation layer, to improve the quality and the efficiency by forming at a high temperature and to improve the forming productivity by quickly and uniformly heating and quickly cooling the surface of a cavity in the mold. CONSTITUTION: Mold cavity surfaces(11,12) are formed by integrated cells(7,8) to be formed by a surface heating layer and a rear insulation layer having an air layer of 20¯90%. The mold cavity surfaces are induction-heated at 50¯400deg.C for 0.5¯20seconds. The temperature of the mold cavity surfaces is cooled within 0.1¯20 seconds by circulating a coolant in a main body of a mold or circulating the coolant in the air layer. Thereby, the heating and the cooling are performed quickly, the uniform temperature distribution is obtained and the flaking problem is solved.

Description

METHOD AND MOLD FOR MOLDING OF PLASTIC ARTICLES

The present invention relates to a method for forming a product and a mold used at this time, and more particularly, by using various conventionally known heating methods to actively and rapidly raise the cavity of the mold, while raising the temperature. A method for forming a product that can improve the quality and performance of a molded product by minimizing the molding cycle time by using a shell having a function of a layer and a heat insulating layer, thereby minimizing the molding cycle time. It is about a mold.

In general, molding of a product such as plastic is performed by injection molding (injection molding), blow molding (hollow molding), thermoforming (thermoforming), and the like, and a molding material heated to a deformable temperature, for example, thermoplastic Material, ceramic, metal, etc. are injected into the mold cavity and then duplicated in the form of the mold cavity, cooled to a temperature that will not deform, and taken out from the mold to produce a molded article.

The molding cycle is repeatedly performed by injecting the molding material into the mold, removing the molded product after molding, and injecting the molding material again, and the time required for the molding cycle represents molding productivity.

As a way to shorten the molding cycle, the cooling time is shortened by making the mold temperature as low as possible. In this case, the cooling time can be reduced, but when the heated molding material is injected into the mold, it meets the low temperature mold cavity surface. Rapid cooling at the interface increases flow resistance, which causes defects on the surface of the molded article, or generates a large amount of stress due to flow, resulting in excessive residual stress after molding in the molded article, thereby degrading the quality of the molded article.

In addition, in the case of a molded article having a long flow path while being thin in thickness, it may be unmolded, and there are various problems such as having to design a thick thickness to prevent this.

In addition, when the molded article is quenched in a mold, crystallization hardly occurs, and the performance of the molded article may not be sufficiently expressed.

In order to improve these points, a method of increasing the temperature of the mold is used. The process of increasing the temperature of the entire mold and then lowering it again is generally performed because the thermal mass is large and the molding cycle time is long, which reduces productivity. Write a way to raise the layer.

A heat insulation layer is comprised between the layer heated up and a metal mold | die main body.

However, these methods do not satisfy the correlation between the elevated temperature and the thermal insulation layer when the temperature difference between the temperature rise and the cooling is large, the correlation between the temperature rise time and the cooling time, and do not significantly reduce the overall molding cycle time. In the process, it is difficult to obtain a uniform temperature on the surface of the mold cavity, or the problem of being limited in controlling the temperature as desired.

For example, U.S. Patent No. 5234637 provides a technique employing an electric heating method and a cooling method using a channel in a mold while forming a heat rising layer of 0.01 to 0.1 mm of copper and a heat insulating layer of an insulating material. In the design of the electrode, it is difficult to obtain a uniform temperature distribution because the electricity is not uniformly flowed, and the thickness of the temperature rising layer and the heat insulation layer is thin, but the cooling effect is excellent. If the coating is difficult and the thickness is not uniform, electricity does not flow uniformly, and thus heat generation is not uniform, resulting in a high risk of overheating and burnout. In particular, when the temperature is elevated under high temperature conditions, Peeling may occur.

In addition, U.S. Patent No. 5064597 provides a technique in which a heating layer and a heat insulating layer are formed in a multi-layered structure having an electric heating method and having a thickness of about 0.25 to 2.54 mm. There is a problem that is difficult to raise the temperature uniformly.

In addition, US Pat. No. 50,047,47 employs a multi-layered structure composed of a heat rising layer such as carbon steel and stainless steel, and a heat insulating layer such as a porous metal and plastic, and provides a technique of cooling through a cooling tube on a mold body. , When the temperature increase layer and the heat insulation layer are combined, the temperature difference between the temperature rise and the cooling occurs greatly shows the limit that the peeling phenomenon can occur, and also only cooling the mold body, so the cooling time is also long.

In other words, many of the existing technologies as described above are designed to have an optimum thickness of the heating layer on the surface of the mold cavity in connection with the aspect of reducing the molding cycle time through an efficient combination of heating and cooling methods, It is difficult to drop and uniformly raise the temperature, and has not been able to suggest a method for shortening the molding cycle time more effectively.

Accordingly, the present invention has been made in view of such a point, and in forming a molded article having an arbitrary curved surface, a heating layer of a low thermal mass constituting a cavity of a mold and a rear surface thereof are formed. Including a shell which performs two functions of an insulation layer having an air layer on the mold, the mold is formed so that peeling of the heating layer and the insulation layer is essentially eliminated, thereby improving durability and improving the quality of the molded product by performing high temperature molding. And improve the performance, and also increase the temperature and cooling effect by using the induction heating method to rapidly and uniformly increase the temperature of the mold surface and circulate the refrigerant in the cooling tube to cool it quickly. At the same time, the molding productivity can be expected to be improved by reducing the molding cycle time. It is an object of the present invention to provide a method for forming a product and a mold for use.

Of course, in the present invention, a method of circulating a high temperature liquid or gas during a heating time in a cooling tube, which is a conventional heating method, for heating the mold cavity surface, and a method of contacting a high temperature object to the cavity surface may be used.

1 is a cross-sectional view showing the overall structure of a mold according to the present invention

2 is a cross-sectional view showing one embodiment of a shell in a mold according to the present invention.

3 is a perspective view showing a cavity of one mold in the mold according to the present invention;

4A-4C are cross-sectional views showing various embodiments of the cross-section along the line A-A of FIG.

5 is a cross-sectional view showing another embodiment of a shell in a mold according to the present invention.

6 is a cross-sectional view and a cross-sectional view taken along line D-D showing an embodiment of the connection structure between the cooling tube and the microchannel in the mold according to the present invention.

7 is a schematic view showing an induction heating method in the molding method according to the present invention

Figure 8 is a perspective view showing the overall configuration including a mold and a heating and cooling device showing an embodiment according to the present invention

9 is a schematic cross-sectional and enlarged view showing one embodiment of a mold according to the present invention.

10 is a perspective view showing one embodiment of a shell in a mold according to the present invention.

11a and 11b are graphs showing an embodiment of the temperature change of the surface of the mold cavity with time during heating and cooling according to the present invention.

12A and 12B are graphs showing another embodiment of the temperature change of the surface of the mold cavity with time during heating and cooling according to the present invention.

Figure 13 is a schematic perspective view showing an embodiment in which the mold according to the present invention is applied to the container molding

Figure 14 is a perspective view showing one embodiment of the induction heating coil used in the molding method according to the present invention

15 is a cross-sectional view taken along the line B-B of FIG.

16A-16C are plan views showing various embodiments of the shell seen in the C direction of FIG. 15.

<Explanation of symbols for main parts of drawing>

1: left side of mold 2: right side of mold

3,4: mold body 5: cavity

6: parting surface 7, 8: shell

9,10: shell receiving portion 11,12: cavity surface

13: shell and mold body joint

14,20: cooling tube 15: micro channel

16: heat rising layer 17: heat insulating layer

18 micro hole 19 shell of nonmagnetic material

21: cooling water line 22: pressure line

23: induction heating coil 24: neck mold of the bottle

25: bottom mold of bottle

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Method for forming a product according to the present invention is a method for forming a product comprising the step of manufacturing a molded article through the cooling step after the injection molding material into the mold, and the temperature rising layer of the surface having a predetermined thickness and A method of forming a mold cavity surface with an integral shell composed of a heat insulating layer having air-filled microchannels on its back, heating the mold cavity surface to a temperature of 50 to 400 ° C. for a time of 0.5 to 20 seconds, and heating the molding material. The process of cooling the mold cavity surface temperature to the desired temperature within 0.5 to 20 seconds by injecting the mold into the mold body to cool the refrigerant by circulating the refrigerant or more actively by circulating the refrigerant in the microchannel of the insulation layer on the back of the mold cavity. Characterized in that consisting of.

In addition, if necessary in the process of constituting the mold cavity surface, a portion of the shell constituting the heating layer and the insulating layer may be replaced with a nonmagnetic material so as to prevent a portion of the mold cavity surface from being heated.

In addition, it is characterized in that the refrigerant can be always circulated through the cooling tube configured in the mold body for cooling efficiency.

In addition, the cooling process can be more actively cooled, which constitutes a cooling tube separate from the cooling tube in the mold body by circulating the refrigerant in the microchannel of the heat insulation layer on the rear of the heating layer. It is characterized in that the refrigerant is circulated by direct connection with the micro channel.

In the heating and cooling process, the circulation of the refrigerant in the microchannel of the heat insulation layer is stopped before the temperature is raised, and the refrigerant is removed from the microchannel by compressed air or vacuum, and then the temperature is raised and the refrigerant is circulated again in the cooling process. It is done.

The mold for molding the product according to the invention is shown in Figure 1 in the left (1), right (2) configuration of the mold including the cavity (5), each of the left and right roles of the cavity surface (11 or 12) 2, which comprises a temperature rising layer 16 having a predetermined thickness and a heat insulating layer 17 formed of a micro channel 15 or a micro hole 18 arranged on the rear surface of the temperature rising layer 16. It is characterized in that it consists of a mold body (3 or 4) including an integral shell, such that the shell is in close contact.

In the drawings, 3 and 4, 7 and 8, 9 and 10, 11 and 12 refer to only one below as the parts on the left (1) and the right (2) of the mold, respectively.

In particular, the material of the shell 8 is characterized in that the magnetic material capable of induction heating when the induction method is applied as a heating method.

In addition, referring to FIG. 3, the shell 8 is in close contact with the shell accommodating portion 10 of the mold main body 4 and forms only the shell 8 and the shell accommodating surface of the mold 8. It is characterized in that it is incorporated at the boundary line 13 between the parts 10, or both the back surface of the shell 8 and the shell receiving portion 10 are combined and integrally combined.

In addition, the thickness of the shell 8 is about 1 to 25 mm, and the thickness of the temperature rising layer 16 is 0.3 to 10.0 mm.

Here, if the thickness of the temperature rising layer is less than 0.3mm, not only the processing is difficult, but also the strength is weak, and there is a problem of impairing the uniformity of temperature. If the temperature exceeds 10.0mm, the thermal mass is too large and not efficient.

In particular, referring to FIGS. 4A to 4C, in the process of configuring the mold cavity, the heat insulation layer 17 is made of a micro channel 15 or a micro hole 18, and the area of the air layer secured in the channel or hole is determined by the heat insulation layer. It is characterized by 20 to 90%.

Here, if the area of the air layer is less than 20%, there is a problem that the heat insulation is insufficient and if the air layer exceeds 90%, the heat insulation is excessive or the strength of the shell 8 due to the molding pressure is weak.

4A to 4C, the microchannel 15 may be formed in a straight line or a wave shape on the rear surface of the heat insulation layer 17.

In addition, the microchannel 15 is characterized in that the width is about 0.3 ~ 10.0mm.

Here, when the width of the microchannel is less than 0.3mm, it is difficult to process and there is a problem in cooling water circulation when circulating the cooling water therein for active cooling, and when it exceeds 10.0mm, there is a problem that the uniformity of the temperature falls.

The micro holes 18 are characterized by having a diameter of about 0.3 to 10.0 mm.

Here, if the diameter of the micro holes is less than 0.3 mm, processing is difficult, and if the diameter exceeds 10.0 mm, there is a problem that the temperature uniformity is inferior.

In addition, referring to Figure 5, if necessary in the process of forming the mold cavity surface, the part of the mold cavity surface in the case of induction heating by replacing a portion 19 of the shell constituting the heating layer and the insulating layer with a non-magnetic material, if necessary The shell may be replaced with a nonmagnetic material so that the temperature is not increased.

In addition, in order to improve the cooling efficiency during the temperature increase and cooling process, to install the cooling tube 14 in the mold body 4 to always circulate the refrigerant through the cooling tube 14 configured in the mold body 4. It features.

In addition, referring to Figure 6, in the case of the method of circulating the refrigerant in the micro-channel of the heat insulating layer during the cooling process, it constitutes a cooling tube 20 separate from the cooling tube 14 in the mold body and the micro-channel and It is characterized in that the cooling tube 20 separate from the cooling tube 14 in the mold main body 4 is directly connected to the microchannel 15 so as to directly perform the cooling.

One embodiment of the method for molding the product and the mold according to the present invention will be described in more detail by employing an induction method as a heating method.

As a method of increasing the temperature of the mold cavity in the process of manufacturing a molded article after cooling the molding material after the injection into the mold, referring to FIG. 7, even when the molded article has a curved surface, the mold cavity may be uniform with respect to the entire volume of the mold cavity. Induction heating method is applied to obtain a temperature distribution.

This induction heating method can be operated in the order in which the induction heating coil 23 is heated in the mold when the mold is opened, and then the induction heating coil is removed and the mold is closed and molded. Since it is comprised, it is an active method which can heat up only a metal mold surface uniformly to a desired temperature quickly.

It is also possible to use direct current flow directly to the heating layer, but in this case, the electrode to be connected with electricity must be attached to the surface of the mold cavity, and even though the design is good, the current flows evenly on the surface of the mold cavity having any curved surface. It is not easy to design and even to raise the temperature evenly.

On the other hand, the induction heating method is a method that can raise the temperature uniformly and quickly by generating an induced current on the surface having any shape.

In the induction heating method, the amount of induced current is inversely proportional to the square of the distance, so that the surface close to the heater is heated up. However, if there is no insulation layer, the temperature rise is not easy due to heat transfer.

In the present invention, however, the more specific layer is heated by constituting the heat thermal layer 16 of the low thermal mass having the heat insulating layer 17 on its rear surface.

The induction heater used in the induction heating method of the present invention is in the form of a heating coil used for high frequency heating and its shape or size may be variable to match the shape of the mold cavity.

That is, in the case of injection molding, as shown in FIG. 7, the induction coil 23 may be manufactured and used in the form of a mold cavity, and in the case of blow molding, as shown in FIG. 15, a shape of a cylinder suitable for heat treatment of the inner surface is shown. It is also possible to use a round coil machined machined round.

If heat insulation is not performed during the temperature raising step in the temperature raising step for the mold cavity, the temperature rising becomes slow and the control of temperature and thermal energy becomes difficult.

Insulating at the same time as the temperature rise can store the energy required for molding in the heating layer, if too much heat insulation is slowed down cooling requires a heat insulating layer of the appropriate thickness.

In the case of circulating the refrigerant in the microchannel of the insulating layer during the cooling step by an active method, the thickness of the microchannel wall may be as thin as not to cause deformation of the shell in the forming step.

Usually, the heating layer and the heat insulation layer are separated due to an imbalance such as heat dissipation and heat stress accumulated. The separation of the functions of the two layers is solved by solving the peeling problem between the heat rising layer and the heat insulation layer. It is preferable to adopt a method of constructing a material which is not used, and the present invention suggests such a preferable method.

For this purpose, the surface of the mold cavity surface having a shell 8 having an arbitrary thickness designed from the shell accommodating portion 10 of the mold body 4, for example, a thickness of about 6 mm, is formed by the temperature raising layer 16. The microchannel 15 whose width | variety is about 0.6-0.8 mm, for example, is machined or discharge-processed in the back surface, and the heat insulation layer 17 is comprised.

The heat insulating layer 17 can secure 20-90%, preferably 65-70%, of the air layer formed by the microchannel 15 on the rear surface thereof, and the thickness of the temperature rising layer 16 is necessary for molding. Correlated with the amount of thermal energy, for example, the microchannel 15 is machined horizontally or deeply into the back of the shell 8 so that the thickness of the heating layer remains 1 mm.

The micro holes 18 may be machined instead of the micro channels 15.

In particular, the structure of the microchannel 15 may be formed in a continuous structure in the horizontal or vertical direction on the back surface of the shell 8, each microchannel 15 is to pass through each other or each independently of the mold body ( It is used in connection with cooling tube (14 or 20) in 4).

The shell 8 thus processed is inserted into the shell accommodating portion 10 of the mold main body 4, and the boundary 13 between the shell 8 and the mold main body 4 at the parting surface 6 of the mold main body 4. )).

If necessary, the surface of the shell accommodating part 10 and the back surface of the shell 8 are coalesced.

As the material of the shell 8, magnetic materials such as iron, nickel, and cobalt capable of induction heating are used, and the material of the mold body 4 may be made of a material having high thermal conductivity. It is also possible to use the same material.

That is, even when the material of the mold main body 4 is the same as the shell 8, the mold main body 4 hardly generates heat since it is inversely proportional to the distance squared during induction heating.

Here, the thickness of the heating layer is closely related to the amount of thermal energy, and the minimum amount of temperature and energy of the mold surface, i.e., the minimum mold surface required to improve the quality or performance of the molded article when the molding material comes into contact with the mold surface. The thermal mass of the mold surface is designed to have thermal energy, and the thickness of the temperature rising layer is designed according to the material of the shell, the set temperature, and the degree of insulation. If a large amount of thermal energy is required, the thickness of the heating layer is designed to be thick.

In consideration of these points, in the present invention, the thickness of the shell is set to 1 to 25 mm and the temperature of the heating layer 16 to 0.3 to 5.0 mm, and the air layer formed by the microchannel 15 or the hole 18 is 20 to 90. It features the shell 8 of the low thermal mass set to about%.

In addition, when the thickness of the temperature rising layer is thick and there is no problem of peeling, for example, when the temperature is 0.5 mm or more, the microchannel is not integrated into the mold body (3) without the temperature rising layer and the heat insulating layer being integrated for ease of mold processing and assembly. It can also be made by inserting and assembling them into the back of the heating layer.

On the other hand, if there is a portion of the mold cavity surface that should not be raised, the shell structure of the portion is made of nonmagnetic material.

Then, only that part of the current is not well induced and thus does not rise.

The cooling method adopted in the present invention is as follows.

In the case of circulating the heating fluid alternately and circulating the cooling fluid during the molding cycle, not only the related equipment becomes complicated but also the total molding cycle time becomes long, and according to the present invention, the method of continuously cooling the mold body 4 during the molding cycle is described. Adopt.

To this end, a cooling tube 14 is provided in the mold main body 4, and a coolant is continuously flowed therein, or the microchannel 15 of the heat insulating layer 17 as well as the mold main body 4 is transferred to the mold main body. By connecting to the cooling tube 14 or 20 of (4), cooling fluid can flow along the microchannel 15 for heat insulation, and it can make cooling more aggressive.

In some cases, before the temperature increase, the cooling fluid in the cooling tube 20 and the microchannel 15 may be removed by compressed air or a vacuum to increase the temperature raising efficiency.

In the molding method according to the present invention, the molding cycle time can be set short while satisfying the improvement of product quality and function, thereby increasing molding productivity.

As shown in FIG. 7, the induction heating of the mold cavity surface, that is, the temperature rising layer 16 of the shell 8, about 50 to 400 ° C. is performed within a short time of about 0.5 to 20 seconds, and then the induction coil 23 is removed. When the mold is closed and the molding material is injected, the thermal energy of the temperature rising layer 16 improves the quality or performance of the molded article at the same time as the mold surface and the molding material are in contact with each other. The mold is opened and the molded article is taken out while cooling to the desired temperature to induce rapid cooling and solidification of the molded article.

In this cooling step, it is possible to further shorten the molding cycle time by forcibly cooling the low thermal mass.

Referring to the embodiment, the entire apparatus is configured as shown in FIG. 8 and a mold having a cylindrical cavity, an induction heating coil 23 for heating the cavity surface, a cooling water line 21 for cooling, and the cooling water is removed during the heating time. It consists of a pressure line 22 for.

9 schematically shows the configuration of the mold in detail.

FIG. 10 is a view showing in detail the shell 8 of the cavity surface in which the temperature raising layer 16 and the heat insulating layer 17 of the cavity surface are integrally formed.

11A and 11B are graphs showing the temperature change of the mold cavity surface with time during heating and cooling.

In this case, the material constituting the mold is ordinary mold carbon steel.

The induction heating power for induction heating was 18 Hz, the frequency was 15.3 Hz, and the cooling water temperature was 15 ° C.

The cavity surface at 95 ° C. is heated to 245 ° C. by induction heating for 1.4 seconds, and FIG. 11A is a case in which the microchannel 15 of the heat insulation layer 17 is naturally cooled without adding special cooling water. 11b shows a case in which the cooling water is circulated and forcedly cooled after natural cooling of 0.6 seconds, and cooled to 95 ° C. in 0.5 seconds.

12A and 12B are enlarged to better show FIG. 11B, FIG. 12A is the same as FIG. 11B, and FIG. 12B is a case where forced cooling is performed after natural cooling for a longer time to 2.8 seconds.

The time or temperature of such natural cooling is set according to the amount of thermal energy necessary to express the best performance and quality of the molded article.

In addition, such optimum process conditions depend on the dimensions of the temperature rising layer and the heat insulating layer and the characteristics of the mold material.

When reheating again, the cooling water that has flowed into the insulation layer for cooling in all cycles can be removed by means of pressure or vacuum to improve heating efficiency.

Such a molding method and a mold according to the present invention can be used for injection molding (injection molding), blow molding (hollow molding), thermoforming (thermoforming) and the like.

An example of application to blow molding is as follows.

By utilizing the present invention in a heat setting process required to increase the heat resistance of a PET bottle, a bottle having high heat resistance can be molded in a fast molding cycle.

In US Pat. No. 4,444,170, heat setting at 200-250 ° C. shows that PET bottles exhibiting heat resistance above 100 ° C., which is quite high, can be produced.

However, US Pat. No. 4,444,170 relies on the circulation of the heated fruit and the cooling fruit at a high temperature and then at a high temperature. In this case, the molding cycle is very long, and thus the commerciality is lowered.

By utilizing the present invention here, it is possible to produce a PET bottle with excellent productivity and excellent heat resistance.

A detailed example is shown in FIG.

The body part of the bottle can be quickly cooled to 250 ° C. using the shell 8 of the present invention and quickly cooled, and the neck part 24 or the bottom part 25 of the bottle is made of a nonmagnetic material to form a shell at low temperature. To maintain or design the thickness of the heating layer and the heat insulating layer different from the thickness of the bottle body portion can maintain a temperature lower than 250 ℃.

Induction heating may be prepared by using an induction heater coil as shown in FIG.

Details of the configuration of the shell 8 and the cooling tube are shown in FIGS. 15 and 16A to 16C.

The direction of the microchannel of the shell 8 in FIG. 15 can be made in the longitudinal or circumferential direction of the bottle as shown in the left or right picture of FIG. 15.

As described above, the present invention uses an integrated shell composed of a heat rising layer having a low thermal mass and a heat insulating layer having an air layer on the back thereof as a mold cavity surface, and a high temperature fluid circulation type or a high temperature for raising the temperature of the mold cavity surface. It is heated and cooled in a short time by using inductive heating method or induction heating method to obtain uniform temperature distribution regardless of product shape, and temperature control and forced cooling method using heat insulation layer. By providing a molding method and a mold that can be distributed and solve problems such as the existing peeling phenomenon, it is possible to improve the quality and performance of the molded products while minimizing the molding cycle time, and overall molding productivity related to the molding of the product. There is an effect to improve.

In addition, it is possible to actively raise the temperature to almost high temperature to improve the quality and performance of the molded products, and can control the temperature increase and heat insulating layers to suit the thermal energy required for molding, so that control is possible and active cooling process The productivity is improved, and the temperature raising layer and the heat insulating layer are formed in one material, thereby improving the durability, and since the metal mold including the heat insulating layer can be easily machined or discharged, there is an industrial practical effect.

Claims (17)

In the method for forming a product comprising the step of injecting the molding material into the mold and the step of heating and cooling to produce a molded article, the temperature rising layer and the surface of the surface having a predetermined thickness in the heating and cooling step 20 ~ 90 The process of constructing the mold cavity surface with an integrated shell composed of a back insulation layer having a% air layer, and heating the mold cavity surface to a temperature of 50 to 400 ° C. at a temperature of 50 to 400 ° C. for a time of 0.5 to 20 seconds, and applying a refrigerant to the mold body. And cooling the mold cavity surface temperature within 0.1 to 20 seconds by circulating and cooling or more actively circulating and cooling the refrigerant in the air layer on the back surface of the mold cavity. The method of claim 1, wherein in the process of forming the mold cavity surface, if necessary, a portion of the shell constituting the heating layer and the insulating layer can be replaced with a nonmagnetic material so that a part of the mold cavity surface is not heated. Method for molding of the product to be made. The method of claim 1, wherein the refrigerant is circulated at all times through a cooling tube configured in the mold body during the temperature raising and cooling. The method of claim 1, wherein in the cooling process, the refrigerant is circulated in the air layer of the heat insulation layer on the rear surface of the heating layer to form a cooling tube or a separate cooling tube in the mold body, and is directly connected to the air layer to circulate the refrigerant. A method for molding a product, characterized in that it is carried out. The method of claim 1 or 4, wherein the circulation of the refrigerant in the air layer of the thermal insulation layer is stopped before the temperature is raised during the temperature raising and cooling process, the refrigerant is removed from the air layer by compressed air or vacuum, and then the temperature is raised and the refrigerant is circulated again in the cooling process. A method for forming a product, characterized in that the process is carried out. In the mold for forming the product is a left and right configuration of the mold including the cavity, each of the left and right serves as a cavity surface and has a heating layer having a predetermined thickness, and the microchannel or micro holes arranged on the rear surface of the heating layer. Mold for molding a product comprising an integral shell consisting of a heat insulating layer is formed of a mold body which is in close contact with the heat insulating layer. The mold as claimed in claim 6, wherein the shell is made of a magnetic material capable of induction heating. 7. The shell of claim 6, wherein the shell is coalesced at the boundary between the shell and the shell accommodating portion only on the surface of the shell body which is in close contact with the shell accommodating portion of the mold body and forms a parting surface between the left and right molds, or both the shell back and the shell accommodating portion are coalesced. And a mold for molding the product, characterized in that it is integrally combined. 9. The mold according to any one of claims 6 to 8, wherein the shell has a thickness of about 1 to 25 mm and the temperature rising layer has a thickness of 0.3 to 10.0 mm. The mold for molding a product according to claim 6, wherein the air layer secured by the heat insulation layer in the process of forming the mold cavity is 20 to 90%. 7. The mold as claimed in claim 6, wherein the microchannels are formed in a straight or corrugated form on the rear surface of the heat insulation layer. The mold according to any one of claims 6, 7, 8, 10 and 11, wherein the microchannels have a width of about 0.3 to 10.0 mm. 7. The mold according to claim 6, wherein the micro holes have a diameter of about 0.3 to 10.0 mm. The non-magnetic portion of the shell of claim 6, wherein a part of the shell forming the mold cavity surface is replaced with a nonmagnetic material, if necessary, to replace the portion of the shell with the non-magnetic material. Mold for forming a product, characterized in that the object can be replaced. The mold for molding a product according to claim 6, wherein a cooling tube is installed in the mold body in order to always circulate the refrigerant through a cooling tube configured in the mold body during the temperature raising and cooling. The mold body of claim 6, wherein in the heating and cooling process, the refrigerant is circulated in the air layer. The mold body may be configured to form a cooling tube or a separate cooling tube in the mold body and directly connect the cooling tube to the air layer to perform cooling. A mold for molding a product, characterized in that the cooling tube inside or a separate cooling tube is directly connected with the air layer. A molded article produced by the molding method of claim 1.